In a manufacturing process of a three-dimensional stack memory, a wafer is damaged by etching during formation of memory holes by etching. To provide a satisfactory crystallinity of silicon pillars formed in the memory holes, a film (hereinafter, also “epitaxial film”) being an underlayer for the silicon pillars is formed by epitaxial growth on the wafer damaged by the etching. Because the epitaxial film has a satisfactory crystallinity, the crystallinity of the silicon pillars formed on the epitaxial film can be improved. After the epitaxial film is formed, a charge accumulation layer is formed on the epitaxial film. A conductive layer is then formed using etching. However, the epitaxial film is conventionally damaged by the etching during formation of the conductive layer. This results in a problem that crystallization of the silicon pillars is inhibited and the property of memory cells is degraded.